胃癌に対する内視鏡的粘膜下層剥離術の最近の進歩：拡大された適応と技術革新に焦点を当てる

The indications for endoscopic resection (ER) and the criteria for the curability of early gastric cancer (EGC) have been expanding. Among Korea, Japan, and Europe, Korea has the most strictly defined indication for ER, followed by Europe and Japan, whereas the curability criteria are relatively similar. Additional surgery is the standard treatment after noncurative resection; however, it is not frequently performed in older patients in clinical practice. Several risk-scoring systems have been developed to further stratify the risk of lymph node metastasis after noncurative resection, and they may help refine the indications for ER and curability assessment in older patients. Nevertheless, the current evidence remains insufficient to establish recommendations specific to this population. In older patients, most deaths are attributable to non-gastric cancer-related causes, regardless of the post-resection treatment strategy. Therefore, in addition to gastric cancer-specific mortality, non-gastric cancer-related mortality and quality of life should be considered. Endoscopic submucosal dissection (ESD) techniques continue to evolve. Traction methods and multibending endoscopes are useful for achieving safe and reliable ESD in selected cases. Although no intervention has been proven effective in reducing delayed bleeding after gastric ESD in randomized controlled trials, several closure methods have shown promising results in retrospective or phase II studies. Furthermore, novel image-enhanced endoscopies may help improve the technical success of gastric ESD. This review provides an evidence-based perspective that may guide optimal management of patients with EGC.